package com.hy.factory;

import com.hy.utils.TransactionManager;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

/**
 * Created With IntelliJ IDEA.
 * Descriptions:代理对象工厂：生成代理对象的
 * author: Mr.Du
 * Date: 2022/9/2
 * Time: 11:35
 */
public class ProxyFactory {
    
    private TransactionManager transactionManager;
    
    public void setTransactionManager(TransactionManager transactionManager) {
        this.transactionManager = transactionManager;
    }
    
    
    /**
     * Jdk动态代理
     * @param obj  委托对象
     * @return   代理对象
     */
    public Object getJdkProxy(Object obj) {
        
        // 获取代理对象
        return  Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(),
                new InvocationHandler() {
                    @Override
                    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                        try{
                            // 开启事务(关闭事务的自动提交)
                            transactionManager.beginTransaction();
                            Object result = method.invoke(obj,args);
                            // 提交事务
                            transactionManager.commit();
                            return result;
                        }catch (Exception e) {
                            e.printStackTrace();
                            // 回滚事务
                            transactionManager.rollback();
                            // 抛出异常便于上层servlet捕获
                            throw e;
                        }
                    }
                });
    }
    
    
    /**
     * 使用cglib动态代理生成代理对象
     * @param obj 委托对象
     * @return
     */
    public Object getCglibProxy(Object obj) {
        return  Enhancer.create(obj.getClass(), new MethodInterceptor() {
            @Override
            public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                try{
                    // 开启事务(关闭事务的自动提交)
                    transactionManager.beginTransaction();
                    Object result = method.invoke(obj,objects);
                    // 提交事务
                    transactionManager.commit();
                    return result;
                }catch (Exception e) {
                    e.printStackTrace();
                    // 回滚事务
                    transactionManager.rollback();
                    // 抛出异常便于上层servlet捕获
                    throw e;
                }
            }
        });
    }
}
